CHOEDATA 



IS 



Fig. 1,005 Salpa fusiformis. A, ag- 

 gregated form ; B, solitary form (Cam- 

 bridge Natural History). Explanations 

 as in Fig. 1,004. 



S. fusiformis Cuvier (Fig. 1,005). Solitary form (8. fusiformis 



Cuv.) a flattened cylinder and with 

 9 muscle bands and 2 short spinose 

 projections at hinder end and 4 to 8 

 cm. long; aggregated form (S. run- 

 cinata Chamisso) with 6 muscle 

 bands, elliptical and 14 to 60 mm. 

 long: cosmopolitan. 



S. (Thalia Blumenbach) demo- 

 cratica Forsk. (Salpa caboti Desor) 

 (Fig. 1,006). Solitary form (S. 

 democratica Forsk.) ovoid, with 2 

 long posterior projections and up to 

 24 mm. long; aggregated form (S. 

 mucronata Forsk.) ovoid, pointed be- 

 hind and up to 15 mm. long; nucleus 

 blue in both forms: cosmopolitan; 



often appearing in immense numbers off the coast of New England; 



the commonest species. 



S. (Pegea Savigny) confffiderata Forsk. Soli- 

 tary form short and wide, pointed behind; 4 



muscles, which are confined to the back; length 4 



to 12 cm.; aggregate form (S. scutigera Cuv.) 



cylindrical, often reddish in color, with 4 muscles ; 



length 7 to 15 cm. : cosmopolitan ; aggregate form 



often common ; solitary form very rare. 



S. (Jasis Lahille) zonaria (Pallas). Solitary 



form elongate, very firm and hard, with 5 very 



broad muscles and 1 narrower posterior muscle 



on the dorsal surface, and up to 6 cm. long; ag- 

 gregate form elongate, ovoid, pointed behind, 



about 24 mm. long; very firm: in all warmer 



seas; Woods Hole; Arctic Seas. 



2. CYCLOSALPA Blainville. Digestive tube 



straight or curved, running antero-posteriorly 



and not coiled up to form a nucleus; salpa chain 



often circular; in other respects like Salpa: 6 



species. 



C. affinis (Chamisso). Aggregated form about 7 cm. long, with ventral 



hatchet-shaped organ of attachment ; apertures terminal ; solitary form 5 



to 10 cm. long, with no longitudinal muscles: Mediterranean; Atlantic 



and Pacific Oceans ; often very plentiful. 



Fig. 1,006 Salpa de. 

 mocratica solitary form 

 (Vogt and Jung). Expla^ 

 nations as in Fig. 1,004. 



